In an assembly line for automobiles and the like, there is needed a bolt having an excellent assembly workability. To meet this, a full dog point bolt having a full dog point extending from the extreme end of the thread portion of a bolt, and a cone point bolt the extreme end of the thread portion of which is coned and the like have been used. In this type of the bolt, the full dog point or cone point acts as a guide for causing the bolt to be threaded into a nut, thereby improving the guide property of the bolt.
Nevertheless, the full dog point bolt has a disadvantage in that the extreme end of the full dog point being formed to a flat shape, the guide property thereof to a nut is not sufficient. Also, the full cone bolt is disadvantaged in that although the cone point thereof can be easily inserted into a nut, it cannot properly guide the direction of the bolt and thus the bolt is obliquely threaded into a nut and the screw thread thereof tends to be broken. Further, in addition to the fact that the bolt must be rolled to make a thread, the cone point of the cone point bolt must be machined and thus a manufacturing cost thereof is expensive.